A healthy 25-year-old right-handed pregnant woman, gravida 1, para 0 at 11 weeks' gestational age, was brought to the emergency department after sending her husband a series of confusing text messages regarding their baby's due date (Figure, A). At the time, she had just concluded a routine visit to her obstetrician's office, where she was retrospectively noted to have difficulty accurately completing her intake form. She additionally recalled an episode of acute weakness of her right arm and leg earlier in the morning that had lasted for a few minutes before resolving and for which she did not seek medical attention.